Up until now, doctors have only been able to use blood tests to detect cancer as long as the patient has already undergone a painful biopsy and sequenced a tumor. However, scientists have now developed a test which can detect cancer in ten minutes using just a drop of saliva. To be priced at $21, the "liquid biopsy" can be taken at home and is hailed as completely revolutionizing the way the disease is diagnosed. Professor David Wong of California State University says it is possible to detect tumor DNA when is it circulating in bodily fluids, noting, "We need...